In recent years, in the field of analytical chemistry, research of μTAS (Micro Total Analysis Systems) are becoming more and more prevalent. A microchip performs various chemical processes such as mixing, chemical reaction, separation and extraction in a minute channel formed, for example, in a chip of several centimeters square. When a chemical process is carried out in a micro size, the interfacial area per unit area where the chemical reaction takes place is larger as compared with the case of performing the chemical reaction in a macro size, so that scale reduction of a chemical apparatus, high-speed processing, reduction of the amount of reagents and the amount of discarding thereof, reduction of the time and higher efficiency of measurement, effects of saving energy, and the like are expected.
A sample solution processed by a microchip has been so far detected by the visible and ultraviolet ray absorption method, the laser spectroscopy method, or the like.
However, these methods are not those in which a plurality of elements are subjected to simultaneous elemental quantification, so that it has been difficult to perform minute analysis of a plurality of elements with a microchip.
On the other hand, as a method for quantitating a plurality of elements simultaneously, the fluorescent X-ray analyzing methods are known. Among these, the total reflection fluorescent X-ray analyzing method by which a primary X-ray is made to enter a sample under conditions of total reflection can measure the fluorescent X-ray coming from the sample surface or the impurities located thereon with a high sensitivity. The total reflection fluorescent X-ray analyzing method provides an advantage in that the angle of entering of the primary X-ray is minute, so that the reflected X-ray or the scattered X-ray hardly enters an X-ray detector, so that the continuous X-ray background noise is smaller as compared with an output level of the fluorescent X-ray detected by an X-ray detector, thereby enhancing the S/B (signal/background) ratio (See Patent Document 1).
Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No. 2003-202306
Non-patent Document 1: M. Claes, P. de Bokx, N. Willard, P. Veny, R. Van Grieken, Spectrochim. Acta part B, 52 (1997) 1063-1070.)